London: Nuclear power could meet all our energy needs but leaves dangerous radioactive waste. Now, a team led by an Indian scientist has developed a new method to reduce the amount of this waste considerably.
The disposal of the old core rods and also reactor operation results in a large amount of low-level waste, especially contaminated cooling water.
S. Narasimhan from the Bhabha Atomic Research Centre in Kalpakkam, India working with P.D. B? Sellergren, a chemist from the Institute of Environmental Research Technische Universit? Dortmund in Germany, developed the method.
His approach: small beads consisting of a special polymer which `fishes` the radioactivity out of the water.
Usually radioactive water is cleaned with ion exchangers. But this technique has a crucial disadvantage, because it doesn`t differentiate between non-radioactive iron-ions and radioactive cobalt-ions.
Sellergren and Narasimhan were looking for a material which binds cobalt and not iron. They developed a special polymer which is made through a procedure called "molecular imprinting".
This polymer is made in an environment containing cobalt. Then the cobalt-ions are extracted with hydrochloric acid, meaning that they are virtually "washed out".
The resulting cobalt-sized holes -- the imprinting -- are able to trap cobalt, and just cobalt, in other environments. The result: a small amount of this polymer can mop up a large amount of radioactive isotopes.
The team is now forming the polymer into small beads that can pass through the cooling system of a nuclear-power station, says a release of the Institute of Environmental Research.
They expect that it would be more economical and environment-friendly to concentrate radioactivity into such beads than to dispose off large amounts of low-level waste.
There obviously is a demand. Some 40 new nuclear-power stations are being built around the world. And the International Atomic Energy Agency estimates that a further 70 will be built in the next 15 years.